What was the advantage of not being able to make our own vitamin C?.There is
usually an advantage for a genetic change to be inherited(eg sickle cell
gene and malaria) and passed to future generations.If there is no advantage
then there is a disadvantage and the offspring are at a greater risk of
disease.
We appear to have a desire for sweet things.We have taste buds that
recognise sweetness .Honey is greatly valued by hunter gatherer societies
but the amount that would be eaten would be limited and seasonal .I think
that it also interesting that we are now becoming more aware of the use of
honey in the treatment of wounds infected with MRSA.It is the abuse of
refinement of carbohydrate that affects our metabolism detrimentally.
Recently the BBC (uk tv )had a programme about the !kung hunting. A group of
men separated an antelope from the herd and their best runner chased it for
8 hours not allowing it to rest or drink.It eventually collapsed and was
killed at close range.A long slow jog .
-----Original Message-----
From: Evolutionary Fitness Discussion List
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Sent: 21 February 2003 21:01
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Subject: EVOLUTIONARY-FITNESS Digest - 20 Feb 2003 to 21 Feb 2003
(#2003-28)
There are 4 messages totalling 163 lines in this issue.
Topics of the day:
1. nice book
2. EVOLUTIONARY-FITNESS Digest - 19 Feb 2003 to 20 Feb 2003 (#2003-27)
3. EVOLUTIONARY-FITNESS Digest - 19 Feb 2003 to 20 Fe...
4. Interesting post
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Date: Thu, 20 Feb 2003 16:42:45 -0500
From: Matt Metzgar <[log in to unmask]>
Subject: nice book
Though there isn't much about exercise, I found "Human Diet: Its Origin and
Evolution" (2002) edited by Peter S. Ungar and Mark F. Teaford to be a very
good read. It gives many perspectives on the Paleo diet and its role in
fighting modern health problems. A summary is at amazon.com.
------------------------------
Date: Fri, 21 Feb 2003 08:09:44 +1000
From: sean mcbride <[log in to unmask]>
Subject: Re: EVOLUTIONARY-FITNESS Digest - 19 Feb 2003 to 20 Feb 2003
(#2003-27)
Yes, I considered this but if there was no physiological/survival pressure
against people with sweet tooths then I wonder why taste sensitivity to
sweetness varies in relation to sweetness in the environment eg my pygmy
example. I don't know if this is widespread but if so I would tend to think
it was a useful adaptation. I could easily be wrong though
Cheers
Sean
> Bit of a naive question: We've got metabolic pathways which process sugars
> quicker than other carbohydrates leading to short term effects (`sugar
> rush'), and (by definition :-) ) sweet things taste different from
> non-sweet things. Both of these effects are reasonably pleasant and when
> strictly moderated by a natural scarcity of sugar dense plants -- and
> certainly without the modern `bred for sweetness' fruits -- don't have any
> deleterous effects on the individual. Is there any reason to believe that
> there was a strong evolutionary pressure causing an interest in sweet
> substances as opposed to there being no physiological/survival pressure
> against people with sweet tooths?
>
> ___cheers,_dave_________________________________________________________
> www.cs.bris.ac.uk/~tweed/ | `It's no good going home to practise
> email:[log in to unmask] | a Special Outdoor Song which Has To Be
> work tel:(0117) 954-5250 | Sung In The Snow' -- Winnie the Pooh
>
> ------------------------------
>
> End of EVOLUTIONARY-FITNESS Digest - 19 Feb 2003 to 20 Feb 2003 (#2003-27)
> **************************************************************************
------------------------------
Date: Thu, 20 Feb 2003 19:29:38 EST
From: Bob Fritz <[log in to unmask]>
Subject: Re: EVOLUTIONARY-FITNESS Digest - 19 Feb 2003 to 20 Fe...
How about virtually everything that was scarce and help survival back then
is
hardwired as a craving today: young women, protein, salt, sugar and dietary
fat?
------------------------------
Date: Fri, 21 Feb 2003 15:27:01 -0500
From: Robert Wolf <[log in to unmask]>
Subject: Interesting post
This is one of the few "good" things I have seen go through the very busy
supertraining list. I have not looked back through the previous posts to
see what prompted this response but it still strikes me that an evolutionary
approach to health and fitness is unique and considered "fringe".
Message: 5
Date: Thu, 20 Feb 2003 15:50:33 -0500
From: "James Krieger" <[log in to unmask]>
Subject: Re: Evolution, endogenous retrovirus, and pseudogenes
James Krieger wrote:
<<...Modern day apes share a common ancestor....Two
pieces of evidence that I consider to be the "smoking guns" are:
1. Shared endogenous retroviruses at the exact same chromosomal locations
between chimps and humans
2. Shared vitamin C pseudogene between apes and men>>
Yehoshua Zohar wrote:
> I have no idea what you are referring to. Can you please put it in
layman's
> terms?
Certainly.
First, let's discuss point #1.
An endogenous retrovirus is a virus that makes a copy of its own genome and
inserts that copy into its host's genome. The HIV virus is an endogenous
retrovirus. The HTLV1 virus is also an endogenous retrovirus and causes a
form of leukemia. Now, if a virus like this inserts a copy of itself into
the germ cell line (the sperm or egg cells), that copy will be passed along
to all future generations of the host. This process is extremely rare.
It's also random, meaning the point in the genome in which the virus inserts
itself varies randomly each time.
Now, imagine a common female ancestor between chimps and humans is infected
with this virus, and the virus inserts itself into the germ cell line. I'm
going to use arbitrary numbers here, but let's say that the virus inserts
itself at position #1000 in the genome. Now, all descendants of that female
will have the virus at position #1000. So, if we find this virus at
position #1000 in both chimps and humans, the only explanation is descent
from a common ancestor, because the chances of a virus inserting itself
randomly at the exact same location in huge genome of two different species
is exceedingly small.
Chimps and humans not only share one retrovirus insertion...they share
seven, all at the same locations. It is practically impossible for seven
viruses to be inserted in the exact same chromosomal locations if it were to
happen by chance. The only plausible explanation is common descent.
Cats give another example of shared retroviral insertions. Small cats, like
domestic cats, share a retroviral insertion with big cats such as lions.
Other carnivores don't have this retroviral insertion.
This also brings up another point about evolutionary theory. Evolutionary
theory, like all scientific theories, are potentially falsifiable. Dogs and
humans don't share a common ancestor (well, at least not a recent one). If
dogs had three retroviral insertions that were unique to humans, then
evolutionary
theory would be falsified. But no evidence such as this has ever turned up.
All
known evidence of shared endogenous retroviruses in living organisms is
consistent with the idea of common descent.
Now let us discuss point #2.
Most species have the capability to make their own vitamin C, so it doesn't
need to be supplied in the diet. Primates do not have this ability. The
reason is that they lack a functional gene that produces an enzyme called
L-gulono-gamma-lactone oxidase (GLO), which is needed to make vitamin C.
However, primates DO have the gene...but a mutation in the gene makes it
non-functional. You and I have the gene to make vitamin C...it just doesn't
work, which is why it's called a "pseudogene." The chances of all the
different species of primates (orangutans, chimps, gorillas, humans, etc.)
all having this exact same mutation is exceedingly small. Again, the only
plausible explanation is that this mutation occurred in our common ancestor,
and the mutation was passed along to all future generations.
I hope this is more clear. Please let me know if it's not and I will try to
illustrate it further.
James Krieger
Graduate Assistant, Nutrition
University of Florida
Webmaster, WSU Strength and Conditioning
http://www.wsu.edu/~strength
Science Editor, Pure Power Magazine
http://www.purepowermag.com
------------------------------
End of EVOLUTIONARY-FITNESS Digest - 20 Feb 2003 to 21 Feb 2003 (#2003-28)
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